Invited review: Are adaptations present to support dairy cattle productivity in warm climates?

Abstract

Environmental heat stress, present during warm seasons and warm episodes, severely impairs dairy cattle performance, particularly in warmer climates. It is widely viewed that warm climate breeds (Zebu and Sanga cattle) are adapted to the climate in which they evolved. Such adaptations might be exploited for increasing cattle productivity in warm climates and decrease the effect of warm periods in cooler climates. The literature was reviewed for presence of such adaptations. Evidence is clear for resistance to ticks and tick-transmitted diseases in Zebu and Sanga breeds as well as for a possible development of resistance to ticks in additional breeds. Development of resistance to ticks demands time; hence, it needs to be balanced with potential use of insecticides or vaccination. The presumption of higher sweating rates in Zebu-derived breeds, based upon morphological differences in sweat glands between breeds, has not been substantiated. Relatively few studies have examined hair coat characteristics and their responses to seasonal heat, particularly in temperate climate breeds. Recently, a gene for slick hair coat has been observed that improved heat tolerance when introduced into temperate climate breeds. No solid evidence exists that hair coat in these lines is lighter than in well-fed warm climate-adapted Holsteins. Warm climate breeds and their F1 crosses share as dominant characteristics lower maintenance requirements and milk yields, and limited response to improved feeding and management. These characteristics are not adaptations to a feed-limited environment but are constitutive and useful in serving survival when feed is scarce and seasonal and high temperatures prevail. The negative relationship between milk yield and fertility present in temperate climates breeds also prevails in Zebu cattle. Fertility impairment by warm conditions might be counteracted in advanced farming systems by extra corporeal early embryo culture. In general, adaptations found in warm climate cattle breeds did not increase heat dissipation capacity, but rather diminished climate-induced strain by decreasing milk production. The negative relationship between reproductive efficiency and milk yield, although relatively low, also appears in Zebu cattle. This association, coupled with limited feed intake, acting over millennia, probably created the selection pressure for a low milk production in these breeds.

Access to shade changes behavioral and physiological attributes of dairy cows during the hot season in the subtropics

“…In order to decrease heat load cows seek shade. Reduced heat production is usually achieved with decreased feed intake, less physical activity as walking or ruminating and lowered milk production (Silanikove, 2000;Berman, 2011;Renaudeau et al, 2012). The choice of which strategy to be used may change depending on weather conditions and on the cow's own characteristics, such as size, body surface, hair coat length and color, as well as metabolic rate (McManus et al, 2011).…”

Copy number variation of individual cattle genomes using next-generation sequencing

“…Indolicidin, the protein product of CATHL4, can induce autophagic cell death in the parasite Leishmana donovani, the causative agent of the parasitic disease Leishmaniasis (Bera et al 2003). This is particularly interesting as the indicine breeds are known for their increased parasite resistance compared to taurine breeds (Berman 2011). Knockouts of CATH-family genes in mice have revealed that the antimicrobial peptide products of Cold Spring Harbor Laboratory Press on May 7, 2018 -Published by genome.cshlp.org Downloaded from these genes influence Leishmaniasis lesion development and tissue colonization of the parasite (Kulkarni et al 2011).…”

“…While both taurine and indicine individuals had CNVs that intersected immune function-related genes, the distinct resistance traits of zebu cattle (Berman 2011) lend great importance to the study of Bos taurus indicus-specific immune function gene CNVs. In that regard, we have identified several CNVs that may represent variations between BINE and the remaining B. t. taurus animals.…”

Adaptability and suitability of local cattle breeds in Egypt: Farmers and actors’ perceptions and practices of the cattle value chain

“…These abilities are referred as adaptability. They mainly rely on functional traits such as reproductive, metabolic, neurological, immunological traits and hair coat characteristics (Berman, 2011). In this study, we determined the adaptive traits perceived by local stakeholders which can be equally relevant to give perspectives on the use of these local breeds in the future.…”